In recent years, with the development of electronic devices having higher performance and a smaller size, a capacitor having a smaller size, a larger capacity, and a lower equivalent series resistance (ESR) has been required. A conductive polymer capacitor using a porous metal foil as an anode and a conductive polymer as a cathode has been known as a capacitor having a smaller size, a larger capacity, and a lower ESR. In general, when a higher electrostatic capacitance is obtained, a dielectric layer is made thinner.
On the other hand, if the dielectric layer of the capacitor is destroyed due to long-term use, inflow of surge or the like, a circuit using the capacitor may be short-circuited. In particular, a capacitor with a dielectric layer made thin to increase the electrostatic capacitance has a low withstand voltage and is in a state of being relatively easily destroyed.
Thus, from the viewpoint of fail-safe, there is known a method of connecting a plurality of capacitors in series so as to prevent the circuit from being short-circuited even when a dielectric layer of one of the capacitors is destroyed. As an element in which a plurality of capacitors are connected in series, a multilayer capacitor in which a dielectric layer and an electrode layer are stacked is known (Patent Document 1). However, the multilayer capacitor as described in Patent Document 1 generates hysteresis characteristics when a ferroelectric is used, and therefore is not necessarily suitable for increasing the capacity in some cases.    Patent Document 1: Japanese Patent Application Laid-Open No. H7-135124    Patent Document 2: Japanese Patent Application Laid-Open No. 2001-203455